For a much better looking version of this post (where code is actually readable!), see this Github repository, which also contains some of the example datasets I use and a literate programming version of this tutorial. Introduction This is a bare-bones introduction to ggplot2, a visualization package in R. It ... [Read more...]

A famous finance professor once told us that good diversification meant holding everything in the world. Fine, but in what proportion? Suppose you could invest in every country in the world. How much would you invest in each? In a market-capitalization weighted index, you'd invest in each country in proportion ... [Read more...]

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The important criterion for a graph is not simply how fast we can see a result; rather it is whether through the use of the graph we can see something that would have been harder to see otherwise or that could not have been seen at all. – William Cleveland, The ... [Read more...]

__ data(quakes)__ head(quakes) lat long depth mag stations 1 -20.42 181.62 562 4.8 41 2 -20.62 181.03 650 4.2 15 3 -26.00 184.10 42 5.4 43 4 -17.97 181.66 626 4.1 19 5 -20.42 181.96 649 4.0 11 6 -19.6... [Read more...]

I’ve recently been scouring the internet for a public opinion data set pertaining to job satisfaction. I was particularly interested in examining how gender, age, and socio-economic status influence how satisfied an individual is with their current employment situation. For example, existing research suggests that women and private-sector employees ... [Read more...]

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Drawing maps of the polar regions can be done using square spatial maps. A small example says more than a thousand words: xlim = c(-180,180) ylim = c(60,90)   # Some fake grid data dat_grid = expand.grid(x = xlim[1]:xlim[2], y… See more › [Read more...]

Following up from my previous post “Code Optimisation: One R Problem, Ten Solutions – Now Eleven!” I figured out a twelfth solution after writing that blog post. Furthermore, half way through writing this blog post I figured out a thirteenth solution too. As a recap, the problem is taken from rwiki ... [Read more...]

Earlier this year I came across a rather interesting page about optimisation in R from rwiki. The goal was to find the most efficient code to produce strings which follow the pattern below given a single integer input n: From this we can see that the general pattern for n ... [Read more...]

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  This is the first in a series of blog posts in which I use the R package GGPlot2 to examine real world data. In this post, I construct a line graph of U.S. shoe consumption from 1995 to 2007. A recent survey conducted by Shop Smart magazine found that the average ... [Read more...]

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Benford's law is an amazing thing. If you know the probability distribution that classes of "natural" numbers should have, you can detect where people might be faking data: phony tax returns, bogus scientific studies, etc. [Read more...]

When estimating the cost of a bunch of purchases, a useful heuristic is rounding to the nearest dollar. (In fact, on US income tax returns, one is allowed to omit the cents). If prices were uniformly distributed, the following two heuristics would be equally accurate: * Rounding each item up or ... [Read more...]

I am writing way too many posts in a row on Google tools. I promise I will think about something else soon. I find amusing the possibility to launch a search in Google images by just dragging a picture into … Continue reading → [Read more...]